Results 1 to 9 of 9

Thread: Torque Control

  1. #1
    Associate Engineer
    Join Date
    Dec 2012
    Posts
    4

    Torque Control

    Bit of a newby here...more of an amateur tinkerer

    I am looking at basically making a propeller type device wherein the propeller (shaft remains still) will turn when I push it with my hands but only when force is applied. Once I let go - I'd like the propeller to stop turning. 1/4 Metal tubing for the shaft, just want to slide the prop on over the tubing. Are there bearings or bushings that will essentially only allow movement when force is applied? This is for a classroom so I appreciate the help!

  2. #2
    Technical Fellow
    Join Date
    Feb 2011
    Posts
    1,043
    Hi, we have a homework policy here that this would fall under, but it's almost christmas so I will give you a little hint. "Drag Clutch!" No, that is not a purse a ...... might take to a Prom dance.

    Picture this -- a light spring over the shaft, a flat metal washer, a flat leather washer (Hardware store Plumbing) the back of the propeller. The strength (compression or wire diameter) of the spring will determine the load to prevent free-spinning.

  3. #3
    Associate Engineer
    Join Date
    Dec 2012
    Posts
    4
    Quote Originally Posted by PinkertonD View Post
    Hi, we have a homework policy here that this would fall under, but it's almost christmas so I will give you a little hint. "Drag Clutch!" No, that is not a purse a ...... might take to a Prom dance.

    Picture this -- a light spring over the shaft, a flat metal washer, a flat leather washer (Hardware store Plumbing) the back of the propeller. The strength (compression or wire diameter) of the spring will determine the load to prevent free-spinning.

    Haha! I appreciate the concern - but I AM the teacher Just failing at trying to demonstrate a point....I will look into this idea you've presented. Thanks!

  4. #4
    Technical Fellow jboggs's Avatar
    Join Date
    Mar 2011
    Location
    Myrtle Beach, SC
    Posts
    776
    What subject do you teach and specifically what is the point you are trying to demonstrate?

  5. #5
    Associate Engineer
    Join Date
    Dec 2012
    Posts
    4
    Might be surprised to know that its not physics.....I teach a couple classes on business and I am a soccer coach. Oddly enough, the device is for teaching a zone principle in soccer. Controlled movement, how one side reacts when another is pressured....love to build things and can usually figure most things out. This one stumped me and a friend of mine told me about this site. Love it!

  6. #6
    Administrator Kelly Bramble's Avatar
    Join Date
    Feb 2011
    Location
    Bold Springs, GA
    Posts
    2,208
    sahft-squeeze.jpg


    The strap material can be bought at and hardware store in the pumbing section. Normally used for hanging pipes (PVC, etc.).

  7. #7
    Technical Fellow
    Join Date
    Feb 2011
    Posts
    1,043
    A rubber band around the blade on the propeller and the shaft. Such that the rubber band drags on the shaft slowing the rotational movement. More rubber bands or smaller (tighter) rubber bands to adjust drag.

    Why am I have such a fixation with "drag?" Might be time to see my therapist again.

  8. #8
    Technical Fellow jboggs's Avatar
    Join Date
    Mar 2011
    Location
    Myrtle Beach, SC
    Posts
    776
    You have to understand that the propeller itself will have some momentum which will cause it to continue rotating after the motivating force is removed. The only thing that will stop it is friction. So you have to control that friction. You want to create something that will rub on the hub of the propeller as it turns. If you can control the force that part exerts on the propeller hub you are controlling the friction. There are lots of ways to do that so maybe you are in the best position to figure out what way suits you best.

  9. #9
    Associate Engineer
    Join Date
    Dec 2012
    Posts
    4
    Quote Originally Posted by PinkertonD View Post
    A rubber band around the blade on the propeller and the shaft. Such that the rubber band drags on the shaft slowing the rotational movement. More rubber bands or smaller (tighter) rubber bands to adjust drag.

    Why am I have such a fixation with "drag?" Might be time to see my therapist again.
    Just an update...I have been goofing off with the spring and washer idea. I appreciate your help especially in this. Haven't dialed it in just yet but thanks!

    Ryan

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •